The present invention relates to a method for manufacturing a temperature sensor element comprised of a lengthy sintered body which extends in an axial direction and is made of insulating ceramic, a sensitive member embedded in the sintered body and a signal output portion for outputting an electric signal received from the sensitive member to the outside.
Conventionally, it has been known that a temperature sensor element has a structure in which a sensitive member is accommodated in a protective tube, such as a metal sheath, a case and a metal tube (see Patent Documents 1, 2 and 3). Such a temperature sensor element detects temperature in such a manner that the temperature of a measurement object conducts and reaches to a sensitive member through the protective tube.
Further, another disclosed temperature sensor element has a structure in which an electrically conductive layer used as the sensitive member is exposed (see Patent Document 4). Such a temperature sensor element detects temperature in such a manner that the electrically conductive layer is directly in contact with a measurement object.
These temperature sensor elements are used for, for example, detecting an exhaust gas temperature of an internal combustion engine, or for detecting temperature of aerospace instruments.                [Patent Document 1] Japanese Patent Application Laid-Open (kokai) No. H10-325759 (FIG. 2)        [Patent Document 2] Japanese Patent Application Laid-Open (kokai) No. 2002-168700 (FIG. 1)        [Patent Document 3] Japanese Patent Application Laid-Open (kokai) No. 2000-266609 (FIG. 2)        [Patent Document 4] Japanese Patent Application based on International Application No. 2003-521118 (Claim 1).        